use super::{

    client::HWClient,

    indexslab::IndexSlab,

    room::HWRoom,

};

use bitflags::*;

use log::*;

use slab;

use std::{borrow::BorrowMut, iter, num::NonZeroU16};

type Slab<T> = slab::Slab<T>;

pub struct HWAnteClient {

    pub nick: Option<String>,

    pub protocol_number: Option<NonZeroU16>,

    pub server_salt: String,

    pub is_checker: bool,

}

pub struct HWAnteroom {

    pub clients: IndexSlab<HWAnteClient>,

}

impl HWAnteroom {

    pub fn new(clients_limit: usize) -> Self {

        let clients = IndexSlab::with_capacity(clients_limit);

        HWAnteroom { clients }

    }

    pub fn add_client(&mut self, client_id: ClientId, salt: String) {

        let client = HWAnteClient {

            nick: None,

            protocol_number: None,

            server_salt: salt,

            is_checker: false,

        };

        self.clients.insert(client_id, client);

    }

    pub fn remove_client(&mut self, client_id: ClientId) -> Option<HWAnteClient> {

        let mut client = self.clients.remove(client_id);

        client

    }

}

pub struct ServerGreetings {

    pub for_latest_protocol: String,

    pub for_old_protocols: String,

}

impl ServerGreetings {

    fn new() -> Self {

        Self {

            for_latest_protocol: "\u{1f994} is watching".to_string(),

            for_old_protocols: "\u{1f994} is watching".to_string(),

        }

    }

}

bitflags! {

    pub struct ServerFlags: u8 {

        const REGISTERED_ONLY = 0b0000_1000;

    }

}

pub struct HWServer {

    pub clients: IndexSlab<HWClient>,

    pub rooms: Slab<HWRoom>,

    pub anteroom: HWAnteroom,

    pub latest_protocol: u16,

    pub flags: ServerFlags,

    pub greetings: ServerGreetings,

}

impl HWServer {

    pub fn new(clients_limit: usize, rooms_limit: usize) -> Self {

        let rooms = Slab::with_capacity(rooms_limit);

        let clients = IndexSlab::with_capacity(clients_limit);

        Self {

            clients,

            rooms,

            anteroom: HWAnteroom::new(clients_limit),

            greetings: ServerGreetings::new(),

            latest_protocol: 58,

            flags: ServerFlags::empty(),

        }

    }

    pub fn add_client(&mut self, client_id: ClientId, data: HWAnteClient) {

        if let (Some(protocol), Some(nick)) = (data.protocol_number, data.nick) {

            let mut client = HWClient::new(client_id, protocol.get(), nick);

            client.set_is_checker(data.is_checker);

            self.clients.insert(client_id, client);

        }

    }

    pub fn remove_client(&mut self, client_id: ClientId) {

        self.clients.remove(client_id);

    }

    pub fn get_greetings(&self, client_id: ClientId) -> &str {

        if self.clients[client_id].protocol_number < self.latest_protocol {

            &self.greetings.for_old_protocols

        } else {

            &self.greetings.for_latest_protocol

        }

    }

    #[inline]

    pub fn create_room(

        &mut self,

        creator_id: ClientId,

        name: String,

        password: Option<String>,

    ) -> RoomId {

        create_room(

            &mut self.clients[creator_id],

            &mut self.rooms,

            name,

            password,

        )

    }

    #[inline]

    pub fn move_to_room(&mut self, client_id: ClientId, room_id: RoomId) {

        move_to_room(&mut self.clients[client_id], &mut self.rooms[room_id])

    }

    pub fn has_room(&self, name: &str) -> bool {

        self.find_room(name).is_some()

    }

    pub fn find_room(&self, name: &str) -> Option<&HWRoom> {

        self.rooms

            .iter()

            .find_map(|(_, r)| Some(r).filter(|r| r.name == name))

    }

    pub fn find_room_mut(&mut self, name: &str) -> Option<&mut HWRoom> {

        self.rooms

            .iter_mut()

            .find_map(|(_, r)| Some(r).filter(|r| r.name == name))

    }

    pub fn find_client(&self, nick: &str) -> Option<&HWClient> {

        self.clients

            .iter()

            .find_map(|(_, c)| Some(c).filter(|c| c.nick == nick))

    }

    pub fn find_client_mut(&mut self, nick: &str) -> Option<&mut HWClient> {

        self.clients

            .iter_mut()

            .find_map(|(_, c)| Some(c).filter(|c| c.nick == nick))

    }

    pub fn all_clients(&self) -> impl Iterator<Item = ClientId> + '_ {

        self.clients.iter().map(|(id, _)| id)

    }

    pub fn filter_clients<'a, F>(&'a self, f: F) -> impl Iterator<Item = ClientId> + 'a

    where

        F: Fn(&(usize, &HWClient)) -> bool + 'a,

    {

        self.clients.iter().filter(f).map(|(_, c)| c.id)

    }

    pub fn filter_rooms<'a, F>(&'a self, f: F) -> impl Iterator<Item = RoomId> + 'a

    where

        F: Fn(&(usize, &HWRoom)) -> bool + 'a,

    {

        self.rooms.iter().filter(f).map(|(_, c)| c.id)

    }

    pub fn collect_clients<F>(&self, f: F) -> Vec<ClientId>

    where

        F: Fn(&(usize, &HWClient)) -> bool,

    {

        self.filter_clients(f).collect()

    }

    pub fn collect_nicks<F>(&self, f: F) -> Vec<String>

    where

        F: Fn(&(usize, &HWClient)) -> bool,

    {

        self.clients

            .iter()

            .filter(f)

            .map(|(_, c)| c.nick.clone())

            .collect()

    }

    pub fn lobby_clients(&self) -> impl Iterator<Item = ClientId> + '_ {

        self.filter_clients(|(_, c)| c.room_id == None)

    }

    pub fn room_clients(&self, room_id: RoomId) -> impl Iterator<Item = ClientId> + '_ {

        self.filter_clients(move |(_, c)| c.room_id == Some(room_id))

    }

    pub fn protocol_clients(&self, protocol: u16) -> impl Iterator<Item = ClientId> + '_ {

        self.filter_clients(move |(_, c)| c.protocol_number == protocol)

    }

    pub fn protocol_rooms(&self, protocol: u16) -> impl Iterator<Item = RoomId> + '_ {

        self.filter_rooms(move |(_, r)| r.protocol_number == protocol)

    }

    pub fn other_clients_in_room(&self, self_id: ClientId) -> Vec<ClientId> {

        let room_id = self.clients[self_id].room_id;

        self.collect_clients(|(id, c)| *id != self_id && c.room_id == room_id)

    }

    pub fn is_registered_only(&self) -> bool {

        self.flags.contains(ServerFlags::REGISTERED_ONLY)

    }

    pub fn set_is_registered_only(&mut self, value: bool) {

        self.flags.set(ServerFlags::REGISTERED_ONLY, value)

    }

}

fn allocate_room(rooms: &mut Slab<HWRoom>) -> &mut HWRoom {

    let entry = rooms.vacant_entry();

    let room = HWRoom::new(entry.key());

    entry.insert(room)

}

fn create_room(

    client: &mut HWClient,

    rooms: &mut Slab<HWRoom>,

    name: String,

    password: Option<String>,

) -> RoomId {

    let room = allocate_room(rooms);

    room.master_id = Some(client.id);

    room.name = name;

    room.password = password;

    room.protocol_number = client.protocol_number;

    room.players_number = 1;

    room.ready_players_number = 1;

    client.room_id = Some(room.id);

    client.set_is_master(true);

    client.set_is_ready(true);

    client.set_is_joined_mid_game(false);

    room.id

}

fn move_to_room(client: &mut HWClient, room: &mut HWRoom) {

    debug_assert!(client.room_id != Some(room.id));

    room.players_number += 1;

    client.room_id = Some(room.id);

    client.set_is_joined_mid_game(room.game_info.is_some());

    client.set_is_in_game(room.game_info.is_some());

    if let Some(ref mut info) = room.game_info {

        let teams = info.client_teams(client.id);

        client.teams_in_game = teams.clone().count() as u8;

        client.clan = teams.clone().next().map(|t| t.color);

        let team_names: Vec<_> = teams.map(|t| t.name.clone()).collect();

        if !team_names.is_empty() {

            info.left_teams.retain(|name| !team_names.contains(&name));

            info.teams_in_game += team_names.len() as u8;

            room.teams = info

                .teams_at_start

                .iter()

                .filter(|(_, t)| !team_names.contains(&t.name))

                .cloned()

                .collect();

        }

    }

}